Ion–water geometry and the Tammann–Tait–Gibson effective pressure and radius

Abstract

An analysis based on X-ray and neutron diffraction data shows that the ion–water geometry can be summarised in terms of the Tammann–Tait–Gibson (T.T.G.) radius of the ion and two angles describing the relative orientations of the ion and water molecule. One angle only depends on I^½(I is the ionic strength) whilst the other angle, α, depends also on the size of the ion. The relative values of α[(α₊–α_K⁺) for the cations and (α_––α_Cl^–) for the anions] are directly proportional to [d(1/T₁)_intra/dm]_{m→ 0} where T₁ is the proton magnetic relaxation rate. The relationship of the T.T.G. effective pressure to the geometry is demonstrated as well.